Sue Lloyd-Roberts interviews a Bosnian police officer who denounces the corruption he has confronted. He describes how difficult it is to fight traffickers. For fear of reprisals, he wants to conceal his identity.

No these raids are not genuine in that sense, these raids never come as a surprise to the owners. Whether they're conducted by the police department or some other department they rarely seem to surprise the owners.

The owners have stated that they would know of a subsequent raid fifteen days in advance. The other thing which is really crucial to mention here is that the girls themselves that have been found there, made statements saying that some senior officials at the Ministry of Interior have been using the services and this has been clarified by the international community.

Do you have personal experience of collusion between bar owners and the police?

Yes I do have personal experience with this. In June last year, while I was driving back from a raid I passed by a particular bar and saw the car that belongs to one of my superiors, outside.

I walked into the bar and saw him flirting with the girls. Some of the girls confirmed later in their statements that they had been forced by the owner to offer sexual favours to him and other senior Bosnian officials.

We have heard that it is quite common for bar owners to reward the police who tip them off about raids by offering their girls for sex?

Yes it is true that because they tip them off, the police do get some sort of favours, free of charge, from the girls who have been forced by the owners to provide services to them.

You saw one of your superiors on good terms with a bar owner receiving sexual favours from the girls, what did you do?

What I could do at that stage was to take statements from the girls and I should have done this in a way that the person in question would never find out. But of course he did find out, and he has started off by offering me a promotion to a senior position.

I have refused this promotion and then he used another approach. He started threatening me, psychologically maltreating me. It is only because of the efforts of the international community, in particular the Stop Team, that I wasn't demoted and maintained my position.

Do the international police task force know about your superior and are they doing anything?

Yes, the international community and the IPTF in particular are familiar with this case and with the sexual favours that are being offered to the senior Bosnian officials and there is an investigation going on but there are no results at this stage so we are still waiting.

The investigation has been going on for some six months now, are you surprised it's taken so long?

Yes I am surprised by how long it is taking. They could have and should have done this long ago. The very fact that the girls gave statements was enough for them to undertake an investigation and bring all the charges in front of the court.

Clearly there are some very good members of the International Police Task Force you work closely with but do you get the impression that there are some at the top who are trying to block these kinds of investigations?

I have had excellent cooperation from IPTF members in the past, but yes I do believe that some senior people at IPTF level are blocking things. I can support this with the fact that I've seen some of the international community members using the sexual favours, at an IPTF level as well as a diplomatic level.

Can you tell me what you know of the internationals using these bars and brothels?

The majority of the international community members that I've seen belong to the SFOR troops, particularly the French and Germans, I've seen them coming in uniforms and having weapons in there.

I also believe they are involved in trafficking and in the issuing of visas. I've also seen people who we could not interrogate because they have diplomatic immunity.

Why are you taking the risk to speak out like this?

The reason I speak out is to make a point not only here but to the whole world that this is something that we should fight against because it actually starts up at the senior level and goes downwards.

There are internationals who come here and earn lots of money. This is money they should spend on stopping trafficking of girls.